How could one be certain if a Swingweight scale is correct without a calibration stick.

I understand we could compare results with another scale,  but if they were different,  how would we know which one is wrong…. both could be wrong.

Is using the math formulas, several of which are online reasonably accurate,  assuming ones measuring skills are precise?

P.s.  i dont have a scale.

Britt Lindsey Answered question October 18, 2022